Attorney’s Docket Number: 18506-1653US3
Filing Date: 4/18/2023
Priority Date: 10/28/2019 (US 16/666,116)
Inventors: Hsieh et al.
Examiner: Marcos D. Pizarro
DETAILED ACTION
This Office action responds to the election filed on 10/7/2025.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . In the event the determination of the status of the application as subject to AIA (or as subject to pre-AIA ) is incorrect, any correction of the statutory basis for a rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Species Restriction
Applicant’s election without traverse of Species 2, reading on figures 2B, 13A and 13B, in the reply filed on 10/7/2025, is acknowledged. The applicant indicates that claims 1-8, 15 and 18-28 read on the elected species. The examiner agrees.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6-8, 15, 20-24 and 26-28 are rejected under 35 U.S.C. 103 as being unpatentable over Lee (US 2018/0312396) in view of Chang (US 2017/0210619).
Regarding claim 1, Lee (see, e.g., figs. 3A, 5A-5N and 6) shows most aspects of the instant invention including a micro electromechanical system (MEMS) structure 300, comprising:
A device substrate 100 having first 310 and second 320 regions
A capping substrate 330/370 bonded over the device substrate
A first cavity 340 in the first region and between the device and capping substrates, wherein the first cavity has a first cavity pressure
A second cavity 350 in the second region and between the device and capping substrates, wherein the second cavity has a second cavity pressure lower than the first pressure
A passivation layer 120/130 in the first cavity, and
An outgassing material (OGM) 200 over the passivation layer, wherein the OGM comprises a bottom portion
Lee, however, fails to show the OGM also comprising a plurality of blocks extending from the bottom portion, wherein one of the blocks comprises a top surface and a sidewall exposed to the first cavity. Chang (see, e.g., par. 0042), on the other hand, teaches that said OGM would achieve relatively a higher pressure due to the increase surface area of the OGM.
Regarding claim 15, Lee (see, e.g., figs. 3A, 5A-5N and 6A) shows most aspects of the instant invention including a MEMS structure comprising:
A device substrate 100
An OGM 200
A passivation layer 120/130 over the device substrate and laterally surrounding at least a portion of the OGM
A capping substrate 330/370 bonded to the device substrate, and
A first cavity 340 defined by the device and capping substrates, wherein a portion of the OGM is in the first cavity, and
A second cavity 350 defined by the device and capping substrates, wherein the cavities have different pressures
Lee, however, fails to show the OGM also comprising a plurality of connected blocks. Chang (see, e.g., par. 0042), on the other hand, teaches that said OGM would achieve a relatively higher pressure due to the increase surface area of the OGM.
Regarding claim 21, Lee (see, e.g., figs. 3A, 5A-5N and 6) shows a MEMS structure comprising:
A device substrate 100 having first 310 and second 320 regions
A capping substrate 330/370 bonded over the device substrate
A first cavity 340 in the first region and between the device and capping substrates, wherein the cavity has a first pressure
A second cavity 350 in the second region and between the device and capping substrates, wherein the cavity has a second pressure lower than the first pressure
A passivation layer 120/130 in the first cavity, and
An OGM 200 over the passivation layer and comprising a bottom portion exposed to the first cavity
Lee, however, fails to show the OGM also comprising a plurality of blocks connected by the bottom portion and exposed to the first cavity. Chang (see, e.g., par. 0042), on the other hand, teaches that said OGM would achieve a relatively higher pressure due to the increase surface area of the OGM.
Regarding claims 1, 15 and 21, it would have been obvious at the time of filing the invention to one of ordinary skill in the art to have the OGM of Lee comprising the blocks of Chang to achieve a higher pressure.
Regarding claims 2 and 22, Lee (see, e.g., fig. 6) shows that the passivation layer 120/130 comprises a recess, and the OGM 200 is in the recess.
Regarding claims 3 and 23, Chang (see, e.g., fig. 29) shows that a bottom of the recess is not exposed from the OGM 1900.
Regarding claim 4, Chang (see, e.g., fig. 29) shows that the OGM 1900 comprises a lower surface between the top surface of the block and a bottom surface of the recess, wherein the lower surface of the OGM is exposed to the first cavity 2808.
Regarding claims 6 and 26, Chang (see, e.g., fig. 29) shows that a top surface of the OGM 1900 concaves toward the device substrate 2000.
Regarding claims 7 and 27, Lee (see, e.g., par. 0059) shows that the OGM comprises oxides.
Regarding claims 8 and 28, Lee (see, e.g., fig. 6) shows that the OGM 200 is free from contacting the capping substrate 330/370.
Regarding claim 20, Lee (see, e.g., fig. 5N) further shows the structure comprising a titanium layer 215 over the device substrate.
Regarding claim 24, Chang (see, e.g., fig. 29) shows that a depth of a space between two adjacent blocks is less than a thickness of the OGM 1900.
Claims 5 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Lee/Chang in view of Liu (US 2018/0222750).
Regarding claims 5 and 25, Lee teaches using an HDP layer as an OGM to control the cavity environment (see, e.g., pars.00059 and 0095). Lee further teaches bonding the device and capping substrates, which involves applying heat during the bonding step (see, e.g., pars. 0101 and 0105). Lee, however, fail to teach that the outgassed species are hydrogen or argon, nor does Lee expressly describe using the heat generated during the bonding step.
Liu teaches using an HDP layer, such as that used by Lee, to outgas hydrogen or argon and to adjust and control the cavity pressure (see, e.g., pars. 0048-0049). Liu further teaches using the heat applied during bonding the device and capping substrates to promote or control outgassing from the HDP oxide layer, thereby adjusting the pressure within the cavity (see, e.g., par. 0015).
One of ordinary skill in the art would have recognized that controlling cavity pressure during device encapsulation is a known desirable result. The teachings of Liu provide a predictable and straightforward way to enhance the pressure control already taught by Lee by specifying suitable outgassing species and leveraging a bonding step already present in Lee’s process.
Accordingly, it would have been obvious to one of ordinary skill in the art at the time of filing the invention to modify Lee’s MEMS structure by incorporating Liu’s teachings of outgassing hydrogen or argon from the OGM, and to use the heat generated during the bonding of the device and capping substrates to adjust cavity pressure. Such a modification would merely involve using a known technique, controlled outgassing during bonding, to improve a similar device, Lee’s sealed cavity, in a predictable manner, thereby yielding the predictable result of controlled pressure.
Claims 18 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Lee/Chang in view of Kang (US 2015/0210541).
Regarding claims 18 and 19, Chang (see, e.g., fig. 29) teaches an OGM 1900 disposed in a cavity 2808 of a microelectronic device, wherein the OGM comprises a plurality of blocks. Chang, however, does not expressly disclose the thickness of the blocks or the spacing between adjacent blocks.
Kang teaches controlling or adjusting the pressure within a sealed cavity by modifying the geometric characteristics of an outgassing material, including changing the area of the OGM and the spacing between adjacent blocks of the OGM (see, e.g., pars. 0035-0036). Although Kang does not explicitly disclose the block thickness or spacing values recited in the claims, Kang clearly teaches that OGM dimensions are result-effective variables for controlling cavity pressure.
One of ordinary skill in the art would have recognized that the thickness and spacing of the OGM blocks directly affect the amount and rate of outgassing, and therefore the resulting cavity pressure. In view of Kang’s teaching that cavity pressure may be adjusted by altering the area and spacing of the OGM, it would have been obvious to one of ordinary skill in the art to select or optimize the thickness and spacing of the OGM blocks in Chang to achieve a desired cavity pressure.
The claimed thickness and spacing values represent no more than the optimization of known result-effective variables, which are considered obvious absent a showing of criticality or unexpected results (MPEP § 2144.05; In re Aller, 220 F.2d 454 (CCPA 1955)).
Conclusion
Papers related to this application may be submitted directly to Art Unit 2814 by facsimile transmission. Papers should be faxed to Art Unit 2814 via the Art Unit 2814 Fax Center. The faxing of such papers must conform to the notice published in the Official Gazette, 1096 OG 30 (15 November 1989). The Art Unit 2814 Fax Center number is (571) 273-8300. The Art Unit 2814 Fax Center is to be used only for papers related to Art Unit 2814 applications.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Marcos D. Pizarro at (571) 272-1716 and between the hours of 9:00 AM to 7:00 PM (Eastern Standard Time) Monday through Thursday or by e-mail via Marcos.Pizarro@uspto.gov. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Wael Fahmy, can be reached on (571) 272-1705.
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/Marcos D. Pizarro/Primary Examiner, Art Unit 2814
MDP/mdp
December 22, 2021